#pragma once

#include "net.hpp"
#include "message.hpp"

namespace rpc {
    class Callback {
    public:
        using ptr = std::shared_ptr<Callback>;
        virtual void onMessage(const BaseConnection::ptr& conn, BaseMessage::ptr& msg) = 0;
    };

    template<typename T>
    class CallbackT : public Callback {
    public:
        using ptr = std::shared_ptr<CallbackT<T>>;
        using MessageCallback = std::function<void(const BaseConnection::ptr& conn, std::shared_ptr<T>& msg)>;

        CallbackT(const MessageCallback& handler)
            :_handler(handler)
        {}

        void onMessage(const BaseConnection::ptr& conn, BaseMessage::ptr& msg) override {
            auto type_msg = std::dynamic_pointer_cast<T>(msg);
            _handler(conn, type_msg);
        }

    private:
        MessageCallback _handler;
    };

    class Dispatcher {
    public:
        using ptr = std::shared_ptr<Dispatcher>;

        template<typename T>
        void registerHandler(MType mtype, const typename CallbackT<T>::MessageCallback& handler) {
            std::unique_lock<std::mutex> lock(_mutex);
            auto cb = std::make_shared<CallbackT<T>>(handler);
            _handlers.insert(std::make_pair(mtype, cb));
        }

        void onMessage(const BaseConnection::ptr& conn, BaseMessage::ptr& msg) {
            // 找到消息类型对应的业务处理函数,进行调用即可
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _handlers.find(msg->mtype());
            if(it != _handlers.end()) {
                return it->second->onMessage(conn, msg);
            }
            // 没有找到指定类型的处理回调 -- 因为客户端和服务端都是我们自己设计的，因此不可能出现这种情况
            // ELOG("收到未知类型的消息: %d!", (int)msg->mtype());
            conn->shutdown();
        }
    private:
        std::mutex _mutex;
        std::unordered_map<MType, Callback::ptr> _handlers;
    };
}